* Due to the limitations of Memcached, clear_all_cache is not implemented. If * you might want to be able to clear your entire cache, then don't use this * handler. However, you can set it up as your first cache and Smarty's disk * cache as your second cache, and check "$smarty->is_cached" before displaying * any cached data; is_cached will check to see if an item is in the disk cache, * which IS affected by clear_all. In that way, you can bypass the Memcached * cache. * * Usage:
* Install this file in the Smarty/plugins directory as * function.memcached_cache_handler.php. Then use the following code: * * include('Your_Smarty_dir/Smarty.class.php');
* include('Your_Smarty_dir/plugins/SmartyMemcached.class.php'); * * $smarty=newSmarty();
* // Add SmartyMemcached configuration, if needed--see below * $smarty->cache_handler_func= * array('SmartyMemcached::cache_handler', 'Smarty::file_cache_handler');
* $smarty->caching = true;
* $smarty->display('index.tpl'); * * Additional configuration:
* By default, the cache handler function assumes that you're running Memcached * on port 11211 of localhost. However, you can use anything you want as your * Memcached server by doing either of the following: * * - Call memcached_cache_handler_set_server with the server name (as a string) * and port (as an int) that's running your Memcached instance. * - Call memcached_cache_handler_set_object with a PECL memcache object that * you've already connected (or pconnected) to. * * If the Memcached instance is shared with any other apps (or, worse, other * users), then use the memcached_cache_handler_set_server function and supply * the optional prefix parameter. Otherwise, you might accidentally retrieve-- * or overwrite--someone else's cached data! * * Credits:
* This code is based heavily upon the MySQL cache handler example from the * official Smarty manual. * * @author Trevor Burnham * @version 1.0 * @package Smarty * @subpackage plugins */ class SmartyMemcached { static $memcache_instance = null; static $key_prefix = ''; /** * Connect to a Memcached server, given a name and port. * * @paramv string server e.g. 'memcached-server.com' or '184.13.134.0'. * @param integer port 11211 is the most common Memcached port. * @return True on success, false otherwise. */ static function setServer($server = 'localhost', $port = '11211') { SmartyMemcached::$memcache_instance = new Memcache(); return SmartyMemcached::$memcache_instance->pconnect($server, $port); } /** * Provide a Memcache object to use for the cache. * * Optionally, a key prefix can be provided; this is STRONGLY recommended if * the Memcached instance is shared with any other applications or users. If * no prefix is supplied, keys are in the format "Smarty:$tpl_file:$cache_id"; * if a prefix is supplied, the format is "$prefix:Smarty:$tpl_file:$cache_id". * A good prefix would be your site's domain name, or an MD5 hash of your home * page--anything that no one else is likely to use. * * (:$compile_id is also appended to the key name if provided. In a pinch, * it could be used as a unique identifier.) * * @param Memcache memcache * @param string prefix */ static function setObject($memcache, $prefix) { SmartyMemcached::$memcache_instance = $memcache; SmartyMemcached::$key_prefix = $prefix; } /** * The cache handler function called by Smarty. * * A read tries Memcached first, then Smarty's file cache. A write stores the * data in both Memcached and the file cache, and a clear removes the data from * both caches. * * @param string action 'read', 'write', or 'clear'. * @param Smarty smarty_obj * @param string cache_content A dummy variable should be used for 'clear's. * Used to supply data for 'write' and to return * data (by reference) on 'read'. * @param string tpl_file * @param string cache_id * @param string compile_id * @param null exp_time * @return boolean True on success, false otherwise. */ static function cache_handler($action, &$smarty_obj, &$cache_content, $tpl_file=null, $cache_id=null, $compile_id=null, $exp_time=null) { if (SmartyMemcached::$memcache_instance == null) SmartyMemcached::setServer(); $memcached_key = $tpl_file.':'.$cache_id; if (SmartyMemcached::$key_prefix != '') $memcached_key = SmartyMemcached::$key_prefix.':'.$memcached_key; if ($compile_id != null) $memcached_key .= ':'.$compile_id; switch ($action) { case 'read': /* Get data from Memcached, if possible. */ $cache_content = SmartyMemcached::$memcache_instance->get($memcached_key); // echo "Read Memcached cache content: $cache_content
"; if ($cache_content == false) { return false; } else { return true; } case 'write': /* Put data in Memcached. */ // echo "Wrote to Memcached: $cache_content
"; return SmartyMemcached::$memcache_instance->set($memcached_key, $cache_content); case 'check': if ($memcache_instance->get($memcached_key) == false) return 'defer'; // The data may still exist in another cache. else return true; case 'check_final': if (SmartyMemcached::$memcache_instance->get($memcached_key) == false) return false; else return true; case'clear': /* Remove the data corresponding to the given key from Memcached. */ return SmartyMemcached::$memcache_instance->delete($memcached_key); default: /* Wow, someone messed up. */ $smarty_obj->_trigger_error_msg( "cache_handler (Memcached):unknownaction\"$action\""); return false; } } } ?>